Assay of Parathyroid Hormone in Human Serum and its Uses

Woodhead, J. S.; Walker, David

doi:10.1177/000456327601300157

Cited by 13 publications

(5 citation statements)

References 18 publications

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“…Detectable PTH in the presence of hypercalcaemia then suggests primary hyperparathyroidism. 13,17 We found measurable PTH in some patients with hypoparathyroidism; why this should occur in idiopathic disease is difficult to explain," although in hypoparathyroidism following neck surgery PTH secretion may continue from damaged or abberently situated glands, but nevertheless be inade~uate to sustain normal calcium homeostasis. 8 The question of the relationship between PTH, PTH-like substances and the hypercalcaemia of malignant disease continues to provoke debate and controversy.…”

Section: Discussionmentioning

confidence: 91%

“…Failure of 'C-terminal' assays to give absolute discrimination between normal subjects and patients with primary hyperparathyroidism is well recognised, 13,14 although better separation may be seen when homologous assay systems are employed.P: 16 In practice, interpretation of PTH values is made with knowledge of the calcium concentration. Detectable PTH in the presence of hypercalcaemia then suggests primary hyperparathyroidism.…”

Section: Discussionmentioning

confidence: 99%

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Performance and Clinical Utility of a Commercially Available ‘C-terminal’ PTH Assay

et al. 1986

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SUMMARY. The performance and clinical utility of a 'C-terminal' parathyroid hormone (PTH) radioimmunoassay (Dac-Cel, Wellcome Diagnostics) is described. Parathyroid hormone, as measured by the Dac-Cel method, is stable in whole blood samples for at least 24 h. 84% of patients with hypercalcaemia due to primary hyperparathyroidism have values above the upper limit seen in normocalcaemic subjects (0,5 ug/L), with detectable serum PTH demonstrable in the remaining 16%. In patients with hypocalcaemia due to hypoparathyroidism serum PTH was undetectable in 73% and 'inappropriately' low in the remainder. In 50% of patients with malignancy-associated hypercalcaemia serum PTH was undetectable, but was above 0·5 ug/L in 13%. Increased PTH concentrations were invariably found in patients with renal failure.The Dac-Cel method is a reliable and robust technique for measurement of PTH and in conjunction with determination of calcium facilitates the diagnosis of primary parathyroid disorders. Caution is required in the interpretation of PTH measurements in patients with renal failure; the significance of detectable PTH in some patients with malignancy-associated hypercalcaemia is not clear.Determination of serum immunoassayable parathyroid hormone (PTH) concentrations forms an important part of the investigation of disorders of calcium metabolism. However, measurement of circulating PTH by radioimmunoassay (RIA) has been bedevilled by the heterogenous nature of circulating PTH and its peripheral metabolism. In recent years, improved understanding of the physiology of PTH secretion and its metabolism, together with the use of well-characterised antisera, has facilitated interpretation of results of PTH in serum. In this report we have evaluated the use of a recently available commercial 'C-terminal' PTH assay (Dac-Cel, Wellcome Diagnostics, Temple Hill, Dartford DA1 5AH, UK) in the investigation of patients with disorders of calcium metabolism. MethodsDac-Cel PTH RIA kits were supplied by

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Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Performance and Clinical Utility of a Commercially Available ‘C-terminal’ PTH Assay

et al. 1986

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“…The detection limit of this method is 0.15 ng/ml and the mean level in normal patients 0.450.5 ng/ml (O'Riordan et al, 1972). The immunoradiometric technique is now well established and compares favourably with radioimmunoassay with respect to both reliability and sensitivity (Woodhead et a!., 1974;Woodhead and Walker, 1976).Free (ionized) calcium values were calculated from total calcium, total protein and albumin using an iterative method described by Hodgkinson and Knowles (1976).Ionized calcium ICa,2+] = where P(Ca) is total calcium, T(a1b) is total albumin and T(g1ob) is total globulin. At pH 7,4 K, is 0.22, X; is 0.22 and K , is 0.05.…”

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confidence: 99%

The nature of hypocalcaemia in acute pancreatitis

McMahon

Woodhead

Hayward

1978

Journal of British Surgery

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A retrospective and prospective study was made of 82 attacks of acute pancreatitis occurring in 80 patients. Attacks were defined as mild (55) or severe (27) according to clinical criteria. Severe attacks were associated with significantly low levels of uncorrected calcium and calculated ionized calcium, both at the time of admission and 48 h later. Patients with severe attacks were found to have lower levels of parathyroid hormone than either those with mild attacks or other patients who had undergone an abdominal operation. These results indicate that severe pancreatitis is associated with true hypocalcaemia, and that deficiency of circulating parathyroid hormone may be a factor in its production.

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“…The situation in rheumatoid arthritis has some resemblance to that pertaining to increased serum ionised calcium concentrations in neoplasm, where in the presence of biochemical evidence strongly suggestive of hyperparathyroidism immunoassay of PTH may be normal (Heath, 1976;Woodhead and Walker, 1976). Conceivably in rheumatoid arthritis and in certain neoplasms polypeptides may be produced which have PTH-like activity but cannot yet be measured by the current immunoassay procedures.…”

Section: Discussionmentioning

confidence: 98%